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Sparky85 06-22-2014 04:08 PM

Cinderblock Foundation issues
I need some advice on what to do with a few foundation issues on my parent's home. I own a property maintenance business, but this is kind of outside my bubble of knowledge.

This is on a early/mid 1970's raised ranch built on a cinder-block foundation. The basement has a french drain around the outer perimeter which has kept it dry for the past 30 years, even with the first issue discussed below. A 20x20 addition was put on with a poured foundation around 2004.

The first issue is the outside of the cinder-block foundation is skim coated in motar/cement - I believe it is called parge? But I am unsure if that is the correct term for this application.
In a few spots it is cracking and falling off. I remember seeing the cracks as a child and its been in the last 5-10 years that chunks have been coming off.

Can this be repaired by chipping away the loose bits and just re-coating? Does it have to go down to the ledge? I'm not sure if this is just above ground or if it goes down the 3-4 feet to the ledge as I have not dug a hole to investigate.

The second issue is a corner of the house where an addition was put on about 10 years ago. The skim coat on the outside was removed on that side of the house exposing the cinder-blocks to the elements, along with a cement driveway. Over the past 10 years from the freeze/thaw cycles of the winter the cinder-blocks are being pushed up and moved around, exposing gaps between them. The slabs of the cement driveway lift up an inch or two from the freeze and settle back down in the spring/summer. This also happens to be where power and phone come into the house from buried utilities, so I will probably need to at least have an electrician/power company take a look at that.

inside view:

I would assume this small corner has to be rebuilt, or should at least be sealed up?

I'll be redirecting the roof's water into the sump with the other pipe you can see and changing the sump pump in the garage with a more powerful pump so it can handle. This is an attempt to keep the space between the house and driveway as dry as possible and reduce the effects of frost heaves. Does this sound good?

So basically A) What can be done for the coating on the cinderblocks that is chipping off, I'm assuming it has helped reduce the weathering of the foundation, and B) What needs to be done with the corner where things are getting shifted around from frost heaves?

EDIT: It appears I am limited to 4 pictures in the post, the album can be found here.

CallMeVilla 06-22-2014 08:19 PM

The skim coat or "parge" can be easily repaired. Just chip it back to solid material then apply stucco patch with a trowel. Let the patch setup for a while then smooth the texture using a rubber face float dipped in clean water. This is an easy fix you can do yourself.

The heaving cinderblocks are much more serious. I am not a cold weather guy, so I will leave advice to them. The look just calls out for "FIX ME NOW" ....

nealtw 06-22-2014 10:45 PM

The corner where the blocks are coming apart, The footing should be at a level below grade to protect it from frost. It appears the the wall is sitting on a ground level footing or is built on top of the garage slab. You will want to dig carefully there not to disturb the power pipe but you want to know how deep the bottom of the footing is and what depth is required where you live.

Sparky85 06-24-2014 02:51 PM

I can't really remember back 15 or 20 years, but I think that corner may have started to crack like that a long time ago from the frost heaves. I know the cracks in the garage floor started about that long ago, now the area of the garage is raised about a 1/2" or so.

About 1/2-2/3 of the house is 3' below the grade, and under that is mostly granite ledge. The garage slab is part of the whole house slab that the foundation is sitting on. The side of the house with the cracking was always level. This is what almost every single house in town is built regardless of style, there are a few with basements mostly or all below the grade, but most are just a couple feet. I know for sinking posts for decks and fences you are required to go down 4' (it was 32" or 3' before the last update to code a few years ago) with the newest codes to get below the frost line.

It looks like I'll be looking for estimates and opinions on the cracked part of the foundation from builders and building engineers to see how we should proceed.

Wuzzat? 06-24-2014 03:57 PM

You may get differing opinions that all sound credible. Not sure where to go from there. . . Credentials of each person? Experience?

I'm more likely to believe someone who wants to run tests but those tests can be expensive.

nealtw 06-24-2014 04:55 PM

If the block walls were built on a pan slab, the side under the wall should have been the required depth for frost protection and should not include the garage slab. The garage is not insulated so it can freeze and move so it should not be tied to the walls. A pan slab has deep sides but you could build on a flat slab if you are going to back fill up the block wall to the required frost depth.
So the question here is how deep is the foundation under that corner of the garage. Perhaps just measure the depth of the pipe the downspout goes into. It is likely the weeping system at or near the bottom of the foundation or footing.

Sparky85 06-24-2014 06:33 PM

The french drain is internal , sorry should have clarified that in my first post. If the slab goes as deep as the rest of the house it is probably near a couple feet down from there. The garage is insulated and sheet rocked, with the exception of the bottom 3' which is just exposed cinder block on the front and that corner.. Yes, it gets cold in the winter, but it never freezes in there. The garage is about 3" lower than the floor in the rest of the basement, so that means it is not connected like you described? Every one of dozens of similar house I have worked in around town are like this.

I talked with my father today about that corner some and the crack on the basement floor. That corner has been cracked since they bought the house 30 some years ago in the early 80's. That side of the house is tied into the addition and that foundation goes down several feet. The walls are all square and plumb as well, floor is level except where the crack in the garage is, so nothing has been shifting around. I'm going to have an engineer look at the issue just to be safe, but at this point it seems safe to just seal it up to prevent water from getting between the blocks and keeping an eye on things over the years.

It also turns out that the drain there is just a drain and the sump pump pumps into that pipe, previously I was under the impression that it all went into the sump and was pumped out. This means it'll be a piece of cake to just re-route the gutters from that 1/4 of the house to that pipe going out into the yard away from the house.

nealtw 06-24-2014 07:17 PM

I don't know atot about block but I would think you could re-point it like brick and then paint it or parge it to make it look nice, With what you have reported here it dosn't seem to be a structure issue.

CallMeVilla 06-29-2014 06:20 PM

Is it reasonable to think about underpinning the corner where the damage has happened? You'd have to allow for the weeping tile system but if the footing is too shallow, then some kind of underpinning might work ... Would require excavation, forming and pouring ... might even require permits.


nealtw 06-29-2014 11:59 PM


Originally Posted by CallMeVilla (Post 107257)
Is it reasonable to think about underpinning the corner where the damage has happened? You'd have to allow for the weeping tile system but if the footing is too shallow, then some kind of underpinning might work ... Would require excavation, forming and pouring ... might even require permits.


I think it is not as bad as it looks . I am leaning toward thinking water got into the blocks and frost, removing the parge and damaging the grout between the brick. There were no complaints about the floor above or house heaving so I don't think it is a footing issue.

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